It came with carbon fiber vinyl on the door handles, gas cap, and trunk lid. I don't mind it.
Some muffler shop special with crush bends, a magnaflow, and a tip were installed, but I haven't had the time to get under it and see how far back it goes. I think it's just an axle back. There's also what looks to be a home-made intake, as the last pipe before the MAF sensor has a bracket welded to it, but it doesn't seem to have any real purpose for mounting in Miata. I may buy another filter and relocate the intake to the passenger side of the engine bay. I'm not sure how effective this is, but it probably looks cleaner. (If you have experience with this, leave your insight)
The clutch fluid was low and looked like crap when I got it, so I bought a 949racing extended stainless clutch line, and installed that, while replacing the clutch slave (the culprit for the low clutch fluid) and bled the entire system out with fresh fluid.
I've always liked the sound of magnaflow exhausts. If its in good shape and you can salvage the muffler, I'd just replace the crush bent section from the cat to the muffler with nice mandrel bent piping. Now what size of pipe I would put would depend on my future goals of what I wanted to do with the car. If I was gonna keep it naturally asperated, I'd go with a 2.25 ID pipe with a perforated resonator. This would give it a nice deep and smooth tone especially with the magnaflow muff. If I was going turbo, I'd go 2.5 ID mandrel bent without a resonator. The turbo will muffle any raspy sound so you wouldn't need a resonator. As far as the intake, the passenger side would be cooler temps but I think (not sure) you'd have to extend the wiring to the MAF.
^I thought about that. If and when I buy a header, I'll probably re-do the exhaust too. I have to measure what the inlet/outlet diameters are on the muffler to see if it will work with the new system.
I think I'll benefit more from a front swaybar first, though.